Duck penises are quite unusual. You may have come across information about Drake online or seen pictures of him. In that case, you probably know that Drake’s genitals are not shaped like a typical phallus but instead have a corkscrew shape.
So, why do ducks have such peculiar reproductive organs? How do they reproduce? And what led to their evolution? We posed these questions to Dr. Patricia Brennan, an evolutionary biologist and an expert on duck penises at Mount Holyoke College in the US. Keep reading to discover why Donald Duck might have been better off wearing pants instead of a sailor shirt.
What is the appearance of a duck’s penis?
“They appear somewhat like tentacles, being pale in color and corkscrew-shaped,” described Brennan.
In certain duck species, the penis undergoes growth and regression during the breeding season. The extent of growth depends on the surroundings. A study led by Brennan in 2017 revealed that Drake’s penis grew considerably longer in the presence of other males compared to those in pairs with females, with some reaching up to 18 cm. An example is the red duck species with a total length of only 39cm.
The lake duck, native to South America, boasts the largest bird penis worldwide and the longest relative to body size, with a specimen from Argentina measuring 42.5 cm in length, compared to the average body length when fully retracted of 36 to 46 cm. For reference, the average erect human penis measures 13 to 18 cm.
Per Guinness World Records, the lake duck’s penis is characterized by barbs at the base and a “soft, brush-like” tip.
A duck’s vagina also has a corkscrew shape, but it spirals in the opposite direction from the penis. “It’s like a maze,” Brennan remarked. “At the entrance, there are several blind pouches followed by a series of narrow spirals.”
How do ducks reproduce?
“Quickly!” exclaimed Brennan. “The male’s penis becomes erect, and since they ejaculate in a third of a second, a brief cloacal contact is needed for insemination.” (If you’re curious, you can watch the video here.) Drake delivers sperm into the female’s vagina near the ovaries.
Why did duck reproductive organs evolve this way?
The unusual genitalia of ducks is a result of a sexual competition. Forced copulation is common among ducks, so the male’s elongated, flexible penis enhances his chances of successfully impregnating the female, while the female’s counterclockwise vagina offers her some control.
“These intricate structures prevent the complete eversion of unwanted males’ penises, causing their sperm to be nearer to the cloaca entrance, making it easier for females to expel the sperm. Thus, Brennan’s research revealed that female ducks can inhibit fertilization from undesired males.
However, if a female desires to mate with a specific male, she can relax her cloacal muscles to facilitate easier access.
About our expert Dr. Patricia Brennan
Dr. Patricia Brennan is an assistant professor of biological sciences at Mount Holyoke College in the United States. She specializes in the evolution of genital morphology and the mechanisms driving reproductive diversification. She has authored numerous research papers on waterfowl reproductive organs.
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Source: www.sciencefocus.com
